Air-brake valve.



No. 794,975. PATENTED JULY 18, 1905. D. s. & J. w. GILBERT. AIR BRAKE VALVE.

APPLICATION FILED JUNE 17, 1904. I

3 SHEETS-SHEET 1.

5, Y g if Al/omey No. 794,975. PATBNTED JULY 19, 1905.

- D. s. & J. w. GILBERT.

AIR BRAKE VALVE.

. APPLICATION FILED JUNE 17. 1994.

' s sums-sum 2.

WITNESSES [NVENTORS flaw/65,5. $025677 3 SHEETS-SHBET 3.

. PATENTED JULY 18, 1905. D. S. & J. W. GILBERT.

AIR BRAKE VALVE.

APPLICATION FILED JUNE 17, 1904.

' Jar/a? 6525;;

NITED STATES Patented July is, 1905 PATENT OFFICE.

DAVID S. GILBERT AND JAMES W. GILBERT, OF READING, PENNSYLVANIA.

AIR-BRAKE VALVE.

SPECIFICATION forming part of Letters Patent No. 794,975, dated July 18, 1905.

Application filed June 17, 1904. Serial No. 213,038.

To all whom it may concern:

Be it known that we, DAVID S. GILBERT and JAMES W. GILBERT, citizens of the United States, residing at Reading, in the county of Berks and State of Pennsylvania, have invented certain new and useful Improvements in Air-Brake Valves; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in air-brakes; and it consists of a novel valve for automatically controlling the brakes exclusively by air-pressure, thus dispensing with springs or other complicated parts.

By means of our valve the brakes are released automatically and instantly on the moment of equalizing the pressure in the air system. We accomplish this automatic action of the air by means of a duplex-valve arrangement which while admitting air under pressure at both ends of the brake-cylinder will permit the full pressure as contained in the auxiliary reservoir to enter only at the rear end and the reduced pressure as contained in the train-pipe to the front end, this cushion of air later acting under expansion to withdraw the brake when pressure is removed from the rear end of the cylinder.

The main objects of our invention are a valve automatically operated controlling both the application and release of the brakes exclusively by air-pressure; the venting of the train-pipe into the front end of the brake-cylinder, cushioning the piston and making a quick-acting valve by further reducing the train-pipe pressurepthe feature of utilizing the full pressure as contained in the auxiliary reservoir upon the brakes, there being no spring to be compressed, as is ordinarily the case, to release the' brakes; a valve which permits a quick equalization of pressure in the auxiliary reservoir, and the fact that our valve, while quick acting, will operate the brakes at extremely low pressure, this being due to the fact already stated that is, there are no springs to compress before the brakes are Set.

A special feature of the valve is that the graduation of the braking power can be regulated to a nicety by means of the train-pipe pressure entering the front end of the brakecylinderthat is, as the air in the train-pipe is reduced the brakes are applied harder, and a complete reduction applies the brakes with full auxiliary pressure.

The invention is more fully described in the following specification and clearly illustrated in the accompanying drawings, in which Figure l is a side view of the valve attached to the brake-cylinder. Fig. 2 is a section through 2 of Fig. 1. Fig. 3 is a view of the brake-cylinder end of the valve. Fig. 4 is a central longitudinal section of the valve-casing, showing the valves therein. Fig. 5 is an end view. Fig. 6 is a section through 6 6 of Fig. 5.

The casing is composed of duplicate barrels 1 and 2, the portion 1 being the casing for the valve intended for applying the brakes and the portion 2 for the valve used in releasing the brakes.

The numeral 3 indicates the inlet from the auxiliary reservoir and leads to the port 4: in

the opposite end of the casing adjacent to the cylinder-head, Fig. 3. From this port is provided an inlet 5 to the valve 6 in the casing, Fig. 4. Also a smaller opening 7 leads from this port into the valve 6 below the piston for the purpose of raising the valve and compressing a spring 8, which is seated in the top of said valve, which spring tends to keep the valve seated when the pressure is equalized.

The numeral 9 indicates the inlet leading to port 10, thence to the rear end of the brakecylinder through inlet 11, and 13 indicates the exhaust therefrom through inlet 9 upon equalization.

The chamber or barrel 2 contains a valve 6, identical with the valve 6; but this valve 6 is provided with a small valve 12 for cushioning it and allowing it to reseat gradually or at least more slowly than the valve 6 in the barrel 1. Entrance to this valve 6 is had from the train-pipe 15 through the inlet 16, and from 15 is arranged a right-angled opening 17, leading to the top of the valves 6 and 6. The in- 1 the valves 6 and 6.

The action is as follows: When the airpressure is reduced in the train-pipe by the usual meansthat is, by the engineer operating the valve on the engine-the air will be drawn from the top of the valves 6 and 6 through the right-angled openings 15 and 17 into the train-pipe. The ball-check 20 will seat itself instantly, closing communication from the train pipe to the auxiliary reservoir through ports 4 and 3. The valves 6 and 6 will be instantly raised by air from port 4: through 7 and cushioning-valve 12, respectively. This action seats valves 21 and 22, which are attached to the piston above, closing exhaust-ports '18 and 1 1. The valve 6 opens port 5 and allows the air to fiow across the'seat, out the inlet 9 into port l0,and through 11 into the rear end of the brake-cylinder, which applies the brake. In the same instant valve 6 opens inlet 16 and the reduced train-pipe pressure flows across the seat and out through 18 at the side, thence into the front end of the brake-cylinder through pipe 19. The brakes are now applied,and the valves will retain this position until the air-pressure is equalized throughout the service by the operator, and when this equalization takes place the valve 6 will seat itself instantly, closing inlet-port 5 and opening exhaust port 13, which exhausts the air from the rear end of the brake-cylinder. The valve 6 in the barrel 2 will also begin to reseat itself, but will be retarded by the action of the cushioningvalve 12, and at this instant of equalization and before the valve 6*has had an opportunity to act fullythat is, to reseat itself-the pressure in the front end of the cylinder will. be increased to the full pressure shown by the gage of the brakes and allowing the pressure of air contained in the front end of the brakecylinder to expand and act on the piston, thus stantaneous recharge of the auxiliary reservoir takes place upon equalization, as ballcheck 20 unseats itself immediately upon the recharge of the train-pipe.

It will be noted that in our construction by dispensing with the use of springs for releasing the brakes we not only simplify the construction of the valve, but accomplish also the economical and effective use of the full amount of air contained in the tank, even if the pressure be low. The graduation of the braking power is so easily controlled as to absolutely prevent the full or emergency application unless desired. In the event of a rupture of the train-pipe the full pressure is applied, as expressed by the gage.

Having thus fully described our invention, what we claim is- 1. An air-brake valve having a double-barreled casing, valves in each of said barrels, one of said valves communicating with the rear end and the other with the front end of the brake-cylinder, whereby the brake is applied and released solely by air-pressure.

2. An air-brake valve comprising a casing composed of two compartments or barrels 1 and 2, spring-backed valves in each of said barrels, a port 4 formed at the back of said casing, a cushioning-valve located in the barrel 2, said barrel 1 being in communication with the rear end and the barrel 2 being in communication with the front end of the brake-cylinder, all substantially as set forth.

3. An air-brake valve comprising a casing composed of two compartments or barrels 1 and 2, spring-backed valves in each of said barrels, a port 4 formed at the back of said casing, acushioning-valve located in the barrel 2, an opening between said barrels connecting port 1 with the auxiliary reservoir, a valve leading from said opening to the top of said valves, said valve in the barrel 1 being in communication with the rear end and the valve in the barrel 2 being in communication with the front end of the brake-cylinder,

whereby the brakes may be applied and released solely by air-pressure.

In testimony whereof we aflix our signatures in presence of two witnesses.

DAVID S. GILBERT. JAMES W. GILBERT.

Witnesses:

ED. A. KELLY, GEO. M. MILLER. 

